How can a safety helmet pass EN 397 and EN 12492?

EN 397 has long been the popular helmet choice for many applications, however a growing need for higher energy and side impact resistance has seen many sites moving to EN 12492 head protection. In some cases both standards are specified, which initially posed a challenge due to seemingly incompatible test requirements.

EN 397 and EN 12492 helmets are intended for different uses. Due to this, there are key contrasts between the impact protection and chinstrap retention requirements set out by each standard.

Impact protection

EN 397 helmets are intended to protect the wearer against objects falling from above and only required to provide impact resistance to the crown area. EN 12492 helmets are designed for use in mountaineering where there is a risk of side impact from swinging, and the standard therefore includes side impact testing.

EN 12492 helmets also offer a higher level of crown impact protection. Testing is carried out at 100J, double the energy required for EN 397 tests.

Despite the variations in requirements, a helmet that passes EN 12492 impact tests will usually pass EN 397 impact tests as well.

Chinstrap requirements

The challenge lies in the chinstrap retention requirements for each standard. As the helmets are intended for different uses, the chinstraps function in different ways.

Chinstraps are optional for EN 397 helmets. If one is fitted, it must release under a specified force for safety, in case the strap becomes caught or snagged on something.

-        EN 397 chinstraps must release when a force of 150-250N is applied.

EN 12492 helmets are designed to maximise protection during a fall. Chinstraps are mandatory, acting as an integral part of the retention system which helps to keep the helmet secure in the event of repeated impacts from swinging or multiple falling objects.

-        EN 12492 chinstraps must not break or stretch when a force of 500N is applied.

These conflicts presented a problem for those needing protection to both standards. It was difficult to find a helmet that satisfied all the requirements, and settling for one option may not be suitable for the task or environment.

Dual protection

Advancements in chinstrap design now enable dual protection to EN 397 and EN 12492, without swapping helmets or replacing the harness.

JSP DualSwitch™ technology allows the release force to be selected using a switchable chinstrap. In EN 397 mode, the chinstrap releases at 150-250N. Switching to EN 12492 mode sets the release force to >500N, activating the mountaineering helmet retention system.

DualSwitch™ technology was first developed for the EVO®5, later rolled out to EVO®VISTA® integrated eyewear helmets, and is now available with the new EVO®ALTA™ range. View DualSwitch™ helmets.

Even with differences in impact testing and opposing chinstrap functions, it is possible to achieve EN 397 and EN 12492 performance with one helmet. The helmet needs to facilitate two different levels of chinstrap release force – allowing it to release at 150-250N for EN 397, whilst staying secure at forces over 500N when EN 12492 protection is required. New helmets fully certified to both standards allow wearers to work safely in applications that call for industrial and mountaineering-style protection.